theremin to midibox... !?

[bosone]

a friend of mine would like that i build a theremin unit for him.

there are plenty of schematics online, for example this one:

http://www.pavekmuseum.org/theremin/diy3.html

according to you... is there a way to collect a 0 / +5V  volt signal from this unit (maybe from the "amplitude" channel)!?!?

if so... one could easy connect a theremin to a midiout and open a whole new world!!!

;D

[Duggle]

hi,

Depending on how fancy you want,  there are various ways to go. One way is to use the amplitude as you suggest by precision recitifying the audio output and lowpass filter to give an envelope signal 0-5V. This would provide info for noteon gating and velocity. If you amplify  the oscillator output to 5Vpk square wave, this could be fed into the PIC CCP input to get a rather accurate pitch determination.  Program logic could be used gate notes with an initial velocity and track their pitch with Pitchbend midi messages and even modulate a CC with the volume envelope.

cheers

[bosone]

i was thinking only about sending a CC with the movement of a hand.

when the hand is far from the volume antenna, CC=0 (or 127, it depends). when i approach the antenna, CC rises and come to 127 (or viceversa).

generating note on/note off would be more complicate (at a first thought).

moreover, if you manage to use also the frenquency antenna (but this could be more complicate), you can have two CC at your hand.

a "virtual theremin" (at least, the one that i have), have only two controllers to play with, and don't use note on/off messages.

this idea is not related to have a midi theremin, but to have a wonderful new control possibility (like the "beam controller" or similar from roland new synths, where you modulate sounds with a hand over a sensor)

[Steven_C]

In case you're interested, there is an article describing a "midi theramin" in Silicon Chip magazine, April 2005. But its not a real theramin (Just sends midi out) and its not a TK and friends midibox!

[DrBunsen]

Or you could build the Theremax from paia.com, which has CV and gate/trig outputs, and use a MIDIbox to convert to MIDI.  And you get a useable Theremin into the bargain.

[Duggle]

hi,

0-5V CV can be derived from the audio output of any theremin (if it does not have CV outs). There are IC's that convert RMS of AC signals into DC signals that can be set to 0 to 5V range. Also frequency to Voltage converter IC's do the same for frequency. This way 2 CC's can be derived from any theremin output.

cheers

[DrBunsen]

The Silicon Chip MIDI Theremin is now available as a complete kit from Jaycar

http://www1.jaycar.com.au/productView.asp?ID=KC5410

$159 AU = about $120 US

[levon]

ive built the jarcar theremin, it works, but it doesnt sound good :(